Documentation
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Index ¶
- Constants
- Variables
- func AcquireLock(ctx context.Context, lockID int) error
- func ActiveAgentCount() int
- func CheckAgents() error
- func ConnectDB(dsn string) error
- func FlushReports(maxErrHours, maxEmptyHours int)
- func HandleDeviceCreate(w http.ResponseWriter, r *http.Request)
- func HandleDeviceDelete(w http.ResponseWriter, r *http.Request)
- func HandleDeviceList(w http.ResponseWriter, r *http.Request)
- func HandleDeviceUpdate(w http.ResponseWriter, r *http.Request)
- func HandleDeviceUpsert(w http.ResponseWriter, r *http.Request)
- func HandleReport(w http.ResponseWriter, r *http.Request)
- func LoadAgents() error
- func PingHosts() ([]model.PingHost, error)
- func PrepareQueries() error
- func ReleaseDB()
- func RequestFromDB(devID int) (model.SnmpRequest, error)
- func RequestWithLock(id int) (model.SnmpRequest, error)
- func SendPingRequests(ctx context.Context)
- func SendPollingJobs(ctx context.Context)
- func SendRequest(ctx context.Context, req model.SnmpRequest, agent Agent) (stCode int, load float64, err error)
- func SnmpJobs() ([]int, error)
- func UnlockDevices()
- type Agent
- type Agents
- type ByLoad
Constants ¶
const ( // DeviceListURI is the api endpoint for device listing DeviceListURI = "/d/list" // DeviceCreateURI is the api endpoint for creating new device DeviceCreateURI = "/d/create" // DeviceUpdateURI is the api endpoint for updating a device DeviceUpdateURI = "/d/update" // DeviceUpsertURI is the api endpoint for `upserting` a device DeviceUpsertURI = "/d/upsert" // DeviceDeleteURI is the api endpoint for deleting a device DeviceDeleteURI = "/d/delete" )
Variables ¶
var ( // MaxLoadDelta is the maximum average load difference allowed between agents // before moving a device to the least loaded agent. MaxLoadDelta float64 = 0.1 // LoadAvgWindow is the window for agent snmp load average calculation. LoadAvgWindow time.Duration )
var ( // LocalIP is the local IP address used for API and report web server. // Defaults to the first non localhost address. LocalIP = getLocalIP() // Port is the web server port Port = 8080 // HTTPTimeout is the timeout in seconds for posting poll requests HTTPTimeout = 3 )
var PingBatchCount int
PingBatchCount is the number of hosts per ping request, set at startup.
Functions ¶
func ActiveAgentCount ¶
func ActiveAgentCount() int
ActiveAgentCount returns the number of current active agents.
func CheckAgents ¶
func CheckAgents() error
CheckAgents sends a keepalive to each agent and updates its status & current load.
func FlushReports ¶
func FlushReports(maxErrHours, maxEmptyHours int)
FlushReports removes old report entries.
func HandleDeviceCreate ¶
func HandleDeviceCreate(w http.ResponseWriter, r *http.Request)
HandleDeviceCreate implements the CRUD create handler
func HandleDeviceDelete ¶
func HandleDeviceDelete(w http.ResponseWriter, r *http.Request)
HandleDeviceDelete implements the CRUD delete handler. The id of the device to delete must be given in `id` param to the POST request.
func HandleDeviceList ¶
func HandleDeviceList(w http.ResponseWriter, r *http.Request)
HandleDeviceList implements the CRUD list handler. When `id` parameter is given to the GET request, returns a json body with the device with this id. Otherwise, returns a json array with all devices ordered by id.
func HandleDeviceUpdate ¶
func HandleDeviceUpdate(w http.ResponseWriter, r *http.Request)
HandleDeviceUpdate implements the CRUD update handler. All device required fields must be defined in the json as for the insert request.
func HandleDeviceUpsert ¶
func HandleDeviceUpsert(w http.ResponseWriter, r *http.Request)
HandleDeviceUpsert implements the CRUD upsert handler. All device required fields must be defined in the json as for the insert request.
func HandleReport ¶
func HandleReport(w http.ResponseWriter, r *http.Request)
HandleReport saves the polling report to db and unlocks the device.
func LoadAgents ¶
func LoadAgents() error
LoadAgents retrieves agent list from db and updates the current agent list (removes deleted, adds new). Note: key for comparision is agent name (host:port).
func PrepareQueries ¶ added in v1.3.0
func PrepareQueries() error
PrepareQueries prepares the db queries
func RequestFromDB ¶
func RequestFromDB(devID int) (model.SnmpRequest, error)
RequestFromDB returns the request with the given device id from db.
func RequestWithLock ¶
func RequestWithLock(id int) (model.SnmpRequest, error)
RequestWithLock builds a model.Request from the given device id and locks the device if there is no error.
func SendPingRequests ¶
SendPingRequests sends current ping requests to agents with load-balancing and agent stickyness
func SendPollingJobs ¶
SendPollingJobs retrieves all available snmp polling jobs and sends each of them sequentially to the next available agent. If the request cannot be sent to an agent, we try the next one until the last. If no agent accepts the job, it is discarded.
func SendRequest ¶
func SendRequest(ctx context.Context, req model.SnmpRequest, agent Agent) (stCode int, load float64, err error)
SendRequest sends the given request to the given agent. Returns the http status code, the agent's current load and an error if unsuccessful.
func SnmpJobs ¶
SnmpJobs returns a list of pollable device ids. A device is pollable if there is no ongoing polling job and was last polled past its polling frequency.
func UnlockDevices ¶
func UnlockDevices()
UnlockDevices retrieves all ongoing requests from all active agents and unlocks all devices without any polling job and whose last job is past its global polling frequency. Is called periodically on a separate goroutine.
Types ¶
type Agent ¶
type Agent struct {
// ID is the agent id
ID int `db:"id"`
// Host is the agent web server IP address
Host string `db:"ip_address"`
// Port is the agent web server listen port
Port int `db:"port"`
// Alive indicates wether this agent responds to keep-alives
Alive bool `db:"is_alive"`
// contains filtered or unexported fields
}
Agent represents an snmp agent
func AgentsForDevice ¶
AgentsForDevice return a list of agents to which send a polling request by order of priority. We try to be sticky as much as possible but with balanced load: - the current list of active agents is sorted by load - if the device is not in jobDistrib map, this list is returned as is. - if the device is in jobDistrib map and its associated agent is active,
- if the load difference between the associated agent and the least loaded agent is under the MaxLoadDelta, we stick to this agent: a modified load-sorted list is returned where this agent is moved at the first position.
- if the load difference exceeds MaxLoadDelta, we rebalance the load: the load sorted list is returned.
Source Files